Magnetotransport Properties of AlxIn1-xAsySb1-y/GaSb and Optical Properties of GaAs1-xSbx Metadata
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- Main Title Magnetotransport Properties of AlxIn1-xAsySb1-y/GaSb and Optical Properties of GaAs1-xSbx
Author: Lukic- Zrnic, ReikoCreator Type: Personal
Chair: Littler, ChrisContributor Type: PersonalContributor Info: Christopher L. Littler ; Major Professor
Committee Member: Golding, TerryContributor Type: PersonalContributor Info: Terry D. Golding ; Minor Professor
Committee Member: Duggan, Jerome L.Contributor Type: Personal
Committee Member: Weathers, Duncan L.Contributor Type: PersonalContributor Info: Duncan L. Weathers
Name: University of North TexasPlace of Publication: Denton, Texas
- Creation: 2003-05
- Digitized: 2003-05-28
- Content Description: Multilayer structures of AlxIn1-xAsySb1-y/GaSb (0.37 £ x £ 0.43, 0.50 £ y £ 0.52), grown by molecular beam epitaxy on GaSb (100) substrates were characterized using variable temperature Hall and Shubnikov-de Haas techniques. For nominally undoped structures both p and n-type conductivity was observed. The mobilities obtained were lower than those predicted by an interpolation method using the binary alloys; therefore, a detailed analysis of mobility versus temperature data was performed to extract the appropriate scattering mechanisms. For p-type samples, the dominant mechanism was ionized impurity scattering at low temperatures and polar optical phonon scattering at higher temperatures. For n-type samples, ionized impurity scattering was predominant at low temperatures, and electron-hole scattering dominated for both the intermediate and high temperature range. Analyses of the Shubnikov-de Haas data indicate the presence of 2-D carrier confinement consistent with energy subbands in GaAszSb1-z potential wells. Epilayers of GaAs1-xSbx (0.19<x<0.71), grown by MBE on semi-insulating GaAs with various substrate orientations, were studied by absorption measurements over the temperature range of 4-300 K. The various substrate orientations were chosen to induce different degrees of spontaneous atomic ordering. The temperature dependence of the energy gap (Eg) for each of these samples was modeled using three semi-empirical relationships. The resulting coefficients for each model describe not only the temperature dependence of Eg for each of the alloy compositions investigated, but also for all published results for this alloy system. The effect of ordering in these samples was manifested by a deviation of the value of Eg from the value of the random alloy. The presence of CuPt-B type atomic ordering was verified by transmission electron diffraction measurements, and the order parameter was estimated for all the samples investigated and found to be larger for the samples grown on the (111) A offcut orientations. This result strongly suggests that it is the A steps that contribute to the formation of the CuPt-B type ordering in the GaAs1-xSbx alloy system.
- Library of Congress Subject Headings: Semiconductors.
- Library of Congress Subject Headings: Alloys.
- Library of Congress Subject Headings: Scattering (Physics)
- Keyword: III-V alloys
- Keyword: scattering mechanisms
- Keyword: Hall mobility
- Keyword: energy gap
- Keyword: atomic ordering
Name: UNT Theses and DissertationsCode: UNTETD
Name: UNT LibrariesCode: UNT
- Rights Access: public
- Rights License: copyright
- Rights Holder: Lukic- Zrnic, Reiko
- Rights Statement: Copyright is held by the author, unless otherwise noted. All rights reserved.
- Thesis or Dissertation
- OCLC: 53241614
- Archival Resource Key: ark:/67531/metadc5522
- Degree Name: Doctor of Philosophy
- Degree Level: Doctoral
- Degree Discipline: Physics
- Academic Department: Department of Physics
- Degree Grantor: University of North Texas